26 
FUR-SEAL FISHERIES OF ALASKA, 1909. 
their inability as pups to provide food for themselves and to escape 
from their natural enemies. It was due also to a heavy death rate 
among these pups on shore from disease. It is altogether probable 
that the death rate from disease on shore that affected pups in 1897 
has since been reduced greatly through the abandonment by seals of 
areas that were supposed to be infected. This would allow a greater 
number of pups to return as yearlings than heretofore and would 
increase the number of bachelors in proportion to the whole herd. It 
would also insure the return of a greater number of yearling females, 
and would assist in maintaining the breeding herd despite pelagic 
killing of cows. It is possible also that the allowance of a 50 per cent 
mortality in pups was too high even in 1897, but I am inclined to 
believe rather that the death rate has changed since then and that 
more pups survive now than formerly. 
The proportion which the pelagic catch bears to the whole herd has 
changed also. In 1897 the pelagic catch, 24,321, bore the same rela- 
tion to the whole herd, 402,850, as 1 to 16. In 1908 it was as 1 to 8 
(18,151 : 146,636). From this it would seem that the pelagic sealers 
are killing twice as many seals in proportion as they did eleven years 
ago. This is another singular fact in connection with the subject, 
showing that conditions at the present time differ entirely from previ- 
ous years. 
It may be that by the methods of estimation used, the number in 
the whole herd in recent years has been placed too low, or rather, 
that there are more seals in the herd than are given in the estimates or 
censuses. It is either in this possibility or the one already men- 
tioned — that the mortality among pups is less than hitherto — that 
the cause of this change of relation of bachelor catch to the whole 
herd must be sought. 
